Effects of oxygen reperfusion and metabolic rate on responses to anoxia in Drosophila melanogaster

LIGHTON, J.R.B. & SCHILMAN, P.E.

San Diego, California

Conferencia; Experimental Biology 2008; 2008

Drosophila melanogaster is highly resistant to anoxic stress. Using a computerized respirometry system to track CO2 flux rates from individual D. melanogaster before, during and after essentially instantaneous and complete exposure to anoxic conditions, we demonstrate the following: (a) Assaying of real-time water vapor output provides a useful index of the neuromuscular integrity of D. melanogaster, and thus of any deleterious effects of anoxia or reperfusion; (b) Evidence suggests that anaerobic metabolic processes power the contraction of spiracular closer muscles during anoxia; (c) CO2 output following anoxia exhibits a biphasic recovery profile, with the second recovery peak possibly corresponding to repair processes; (d) Single or multiple brief (60 sec) reperfusions with oxygen, followed by return of anoxic conditions, cause physiologically evident reperfusion damage in a dose-dependent fashion; and (e) Changing the metabolic flux rate of D. melanogaster has no systematic effect on the temporal kinetics of its recovery from anoxia. For example, doubling the metabolic flux rate has no significant effect on the length of time required for recovery from anoxia. The implications of these findings are discussed.